In copending application Ser. No. 07/417,775, filed Oct. 6, 1989 (the disclosure of which is hereby incorporated by reference herein), a method and apparatus are provided for essentially automatic sealing of business forms using pressure sensitive adhesive rather than heat activated adhesive. The method and apparatus disclosed in that patent application are very effective and have broad applicability. However, that procedure is slightly more complex than necessary for some uses, and may handle the business forms (documents) in a somewhat undesirable manner under other circumstances.
According to the present invention, an extremely simple, inexpensive, and straight forward pressure sealer is provided which is designed to handle business forms on a manual feed or semi-manual feed basis. When utilizing the apparatus of the above mentioned patent application, due to a jam or paper misfeed some of the documents may not make it all the way through the sealer. It is impractical to feed those documents through again; however, utilizing the machine according to the invention, those documents can be manually run through to be sealed in a very simple yet effective manner. Also, there are some documents that require special processing due to data sensitivity or other special handling requirements, and those documents are best hand fed rather than acted upon automatically. Further, if there is a need merely to seal a very few documents, either to finish out a batch, or for an odd mailing in a small business, or the like, the simple, easy to use machine according to the invention is highly desirable.
According to one aspect of the present invention, a basic manual feed pressure sealer is provided for sealing adhesive strips of pressure sensitive adhesive associated with business forms. The apparatus comprises the following elements: A frame. Conveying means for conveying a business form past the frame, the conveying means consisting essentially of a first narrow width roller rotatable about a first horizontal axis, a second narrow width roller rotatable about a second horizontal axis, a drive motor, and gearing means interconnecting the drive motor to the first and second rollers. And, pressure applying means for applying pressure to the business forms when being conveyed in a first direction along a line tangent to both the first and second rollers, the pressure applying means comprising third and fourth narrow width rollers rotatable about third and fourth axes parallel to and aligned with the first and second axes, respectively, and means for biasing the third and fourth rollers toward contact with the first and second rollers so that as a business form is conveyed by the first and second rollers pressure is applied thereto by the third and fourth rollers. The gearing means preferably comprises only three gears, made of Delrin or like plastic, a pinion gear driven by the motor, and meshing with two other gears, one integral with each of the first and second rollers. The third and fourth rollers preferably comprise sections of ball bearings. The frame includes a platform leading to the first roller, and has a flap to prevent pinching of the operator's fingers. Spring pressure is applied to the third and fourth rollers with a mechanism that provides adjustment of the spring pressure, or can be completely disabled to release all spring pressure and allow easy inspection and/or replacement of the components.
The spring pressure applying means comprises: a stationary flange mounted on the frame and having a screw threaded opening therein of a first diameter; a spring pressure adjusting collar having a screw threaded opening therein of the first diameter; a coil spring; and a spring positioning plate. The spring pressure adjusting collar is disposed on the underside of the flange with the screw threaded openings therein in alignment; the spring engaging the adjusting collar at one end thereof, and operatively engaging the plate at the other end thereof. A first bolt has external screws with the first diameter and has a length less than the length from the flange to the plate when the spring is in extended position, the spring biasing the plate into operative engagement with the third and fourth rollers to apply a spring pressure thereto. Also, the spring positioning plate has a screw threaded opening therein having a second diameter, smaller than the first diameter; and wherein the spring biasing means further comprises a second bolt, interchangeable with the first bolt, and having external threads thereon of the second diameter, and having a length greater than the length from the flange to the plate when the spring is in extended position.
Desirably, roller yokes are provided for the third and fourth rollers, each roller yoke operatively attaching a roller to the frame for rotation about its axis and for relative movement toward and away from the first and second rollers. Each roller yoke has means for engaging the spring positioning plate so that the bias of the coil spring is applied to the third and fourth rollers through the spring positioning plate and the roller yokes. Each of the roller yokes is releasably pivotally mounted to the frame about its own yoke axis so that when the second bolt is fully threaded into the spring positioning plate the spring is compressed so that the roller yoke may be pivoted about its yoke axis and disconnected from the frame, but when the first bolt is in operative association with the flange the pressure of the spring prevents the yokes from being significantly pivotally movable about the yoke axes.
The biasing means also preferably comprises a spring button having a through extending opening therein large enough to allow clear passage of the second bolt therethrough, a spring positioning central post, and a rounded head engaging the spring positioning plate. The coil spring engages the head on the opposite side thereof from the plate, and surrounds the post, and operatively engages the spring positioning plate through the head.
The invention also contemplates a method of handling business forms. The method comprises the steps of: (a) manually feeding a business form into operative association with the rollers so that the rollers apply pressure to one of the plurality of pressure sensitive adhesive strips to seal the business form together at that strip; and (b) after step (a), repeating manually moving the business form into operative association with each of the other unsealed adhesive strips, in turn, until all desired adhesive strips of the business form have been sealed. The force being applied by the rollers is only applied to the approximate area of the predetermined width of adhesive of each strip.
It is a primary object of the present invention to provide a simple and effective method and apparatus for pressure sealing of business forms. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.